In Situ Immunofluorescence Imaging of Vital Human Pancreatic Tissue Using Fiber-Optic Microscopy.

Purpose: Surgical resection is the only curative option for pancreatic carcinoma, but disease-free and overall survival times after surgery are limited due to early tumor recurrence, most often originating from local microscopic tumor residues (R1 resection). The intraoperative identification of microscopic tumor residues within the resection margin in situ could improve surgical performance. The aim of this study was to evaluate the effectiveness of fiber-optic microscopy for detecting microscopic residues in vital pancreatic cancer tissues. Experimental Design. Fresh whole-mount human pancreatic tissues, histological tissue slides, cell culture, and chorioallantoic membrane xenografts were analyzed. Specimens were stained with selected fluorophore-conjugated antibodies and studied using conventional wide-field and self-designed multicolor fiber-optic fluorescence microscopy instruments. Results: Whole-mount vital human tissues and xenografts were stained and imaged using an in situ immunofluorescence protocol. Fiber-optic microscopy enabled the detection of epitope-based fluorescence in vital whole-mount tissue using fluorophore-conjugated antibodies and enabled visualization of microvascular, epithelial, and malignant tumor cells. Among the selected antigen-antibody pairs, antibody clones WM59, AY13, and 9C4 were the most promising for fiber-optic imaging in human tissue samples and for endothelial, tumor and epithelial cell detection. Conclusions: Fresh dissected whole-mount tissue can be stained using direct exposure to selected antibody clones. Several antibody clones were identified that provided excellent immunofluorescence imaging of labeled structures, such as endothelial, epithelial, or EGFR-expressing cells. The combination of in situ immunofluorescence staining and fiber-optic microscopy visualizes structures in vital tissues and could be proposed as an useful tool for the in situ identification of residual tumor mass in patients with a high operative risk for incomplete resection.

Immunologic landscape of human hepatic hemangiomas and epithelioid hemangioendotheliomas.

BACKGROUND: The missing requirement for resection for the majority of hepatic hemangiomas (HH) and tissue scarcity for rare diseases such as hepatic epithelioid hemangioendotheliomas (HEHE) complicate the characterization of the spatial immunovascular niche of these benign and malignant vascular neoplastic diseases. METHODS: Two tissue cohorts containing 98 HHs and 13 HEHEs were used to study entity-specific and disease stage-specific endothelial cell (EC) phenotype and immune cell abundance. Using semiquantitative assessment, annotation-based cell classifiers, digital cell detection on whole slides, and tissue microarrays, we quantified 23 immunologic and vascular niche-associated markers and correlated this with clinicopathologic data. RESULTS: Both HH and HEHE ECs were characterized by a CD31high, CD34high, FVIII-related antigenhigh expression phenotype with entity-specific expression differences of sinusoidal EC markers Stabilin1, Stabilin2, CD32, and Lymphatic Vessel Endothelial Hyaluronan Receptor 1 (LYVE-1). Cell detection identified an HH margin-prevailing immunologic response dominated by Myeloperoxidase+ (MPO+) macrophages, CD3+ and CD8+ T cell subsets, and B cells (CD20+, CD79A+). In HEHE, increased CD68+ and CD20+ cell demarcation of lesion margins was observed, while CD3+ and CD8+ T cells were equally detectable both marginally and intralesionally. Stage-specific pairwise correlation analysis of HH and HEHE revealed disease entity-specific immunologic infiltration patterns as seen by high CD117+ cell numbers in HH, while HEHE samples showed increased CD3+ T cell infiltration. CONCLUSIONS: ECs in HH and HEHE share a continuous EC expression phenotype, while the expression of sinusoidal EC markers is more highly retained in HEHE. These phenotypic differences are associated with a unique and disease-specific immunovascular landscape.

Digital Staging of Hepatic Hemangiomas Reveals Spatial Heterogeneity in Endothelial Cell Composition and Vascular Senescence.

Hepatic hemangioma (HH) is the most common benign primary liver tumor; however, despite its high prevalence, a stage-specific classification of this tumor is currently missing. For a spatial stage-specific classification, a tissue microarray (TMA) consisting of 98 HHs and 80 hemangioma margins and 78 distant liver tissues was digitally analyzed for the expression of 16 functional and vascular niche-specific markers. For cross-correlation of histopathology and functional characteristics, computed tomography/MRI imaging data of 28 patients were analyzed. Functional and morphological analyses revealed a high level of intra- and interpatient heterogeneity, and morphological heterogeneity was observed with regard to cellularity, vascular diameter, and endothelial cell subtype composition. While regressed hemangiomas were characterized by low blood vessel density, low beta-catenin levels, and a microvascular phenotype, non-regressed HHs showed a pronounced cellular and architectural heterogeneity. Functionally, cellular senescence-associated p16 expression identified an HH subgroup with high vascular density and increased lymphatic endothelial cell content. Histological HH regions may be grouped into spatially defined morphological compartments that may reflect the current region-specific disease stage. The stage-specific classification of HHs with signs of regression and vascular senescence may allow a better disease course-based and cell state-based subtyping of these benign vascular lesions.

YAP-induced Ccl2 expression is associated with a switch in hepatic macrophage identity and vascular remodelling in liver cancer.

BACKGROUND & AIM: The development of hepatocellular carcinoma (HCC) is associated with the formation of communication networks leading to the recruitment of disease-modifying macrophages. However, how oncogenes in tumour cells control paracrine communication is not fully understood. METHODS: Transgenic mice with liver-specific expression of the constitutively active yes-associated protein (YAPS127A ) or an orthotopic implantation model served as tumour models. FACS-sorted F4/80+ /CD11bdim /CD146- /retinoid- macrophages from healthy and tumour-bearing livers were used for transcriptomic profiling. Expression data of 242 human HCCs and a tissue microarray consisting of 91 HCCs and seven liver tissues were analyzed. RESULTS: Screening of primary tumour cells expressing YAPS127A identified CC chemokine ligand 2 (Ccl2) as a macrophage chemoattractant, whose expression was regulated in a YAP/TEA domain family member 4 (TEAD4)-dependent manner. Ccl2 expression was associated with a loss of Kupffer cells (KCs) and an increase in immature macrophages (Mɸimm ) in hepatocarcinogenesis. Recruited Mɸimm were characterized by a lack of functional polarization (M0 signature) and high expression of the Ccl2 receptors C-C motif chemokine receptor 2 (Ccr2), C-X3-C motif chemokine receptor 1 (Cx3cr1) and pro-angiogenic platelet-derived growth factors (Pdgfa/Pdgfb). Mɸimm formed cellular clusters in the perivascular space, which correlated with vascular morphometric changes indicative for angiogenesis. In human HCCs, the M0 signature served as an identifier for poor clinical outcome and CCL2 correlated with YAP expression and vascular network formation. CONCLUSIONS: In conclusion, YAP/TEAD4-regulated Ccl2 associates with perivascular recruitment of unpolarized Mɸimm and may contribute to a proangiogenic microenvironment in liver cancer.

Measurement and evaluation of gaseous and particulate emissions from burning scented and unscented candles.

It has been known for a long time that incomplete combustion processes produce by-products that are harmful to human health. Particularly high concentrations of such by-products can arise in indoor environments when operating open flames without venting. The emission behavior of many combustion sources, including candles, has already been examined in detail. However, to date there are no studies in which the chemical composition of the candles is known exactly or where the candles were specifically manufactured for comparative measurements. In this respect, the study presented here, which was designed in collaboration with candle manufacturers and fragrance houses, demonstrates new insights into the emissions of burning candles depending on their composition. All investigations were carried out under controlled climatic conditions in an 8 m3 stainless steel chamber. Combinations of four different fuels (waxes) and five different fragrances in addition to one set of unscented control candles were examined. This resulted in 24 experiments, 20 with scented candles and four with unscented candles. The typical combustion gases carbon monoxide, carbon dioxide and NOx, organic compounds, such as formaldehyde, benzene, and polycyclic aromatic hydrocarbons, PM2.5 and ultrafine particles were monitored in the chamber air and the emission rates were determined. The data were statistically evaluated using parametric and non-parametric methods as well as hierarchical cluster analysis. Exposure scenarios typical for indoor environments were calculated from the emission rates and the results were compared with indoor guidance and reference values. As expected, a multitude of gaseous and particulate emissions were detected. These were typical combustion products as well as evaporated constituents of the fragrance mixtures. In most cases, the calculated indoor concentrations were well below the respective guidance and reference values. The exceptions observed in some cases for nitrogen dioxide, acrolein and benzo[a]pyrene are discussed critically.

Yes-associated protein (YAP) induces a secretome phenotype and transcriptionally regulates plasminogen activator Inhibitor-1 (PAI-1) expression in hepatocarcinogenesis.

BACKGROUND: Overexpression and nuclear enrichment of the oncogene yes-associated protein (YAP) cause tumor initiation and support tumor progression in human hepatocellular carcinoma (HCC) via cell autonomous mechanisms. However, how YAP expression in tumor cells affects intercellular communication within the tumor microenvironment is not well understood. METHODS: To investigate how tumor cell-derived YAP is changing the paracrine communication network between tumor cells and non-neoplastic cells in hepatocarcinogenesis, the expression and secretion of cytokines, growth factors and chemokines were analyzed in transgenic mice with liver-specific and inducible expression of constitutively active YAP (YAPS127A). Transcriptomic and proteomic analyses were performed using primary isolated hepatocytes and blood plasma. In vitro, RNAinterference (RNAi), expression profiling, functional analyses and chromatin immunoprecipitation (ChIP) analyses of YAP and the transcription factor TEA domain transcription factor 4 (TEAD4) were performed using immortalized cell lines. Findings were confirmed in cohorts of HCC patients at the transcript and protein levels. RESULTS: YAP overexpression induced the expression and secretion of many paracrine-acting factors with potential impact on tumorous or non-neoplastic cells (e.g. plasminogen activator inhibitor-1 (PAI-1), C-X-C motif chemokine ligand 13 (CXCL13), CXCL16). Expression analyses of human HCC patients showed an overexpression of PAI-1 in human HCC tissues and a correlation with poor overall survival as well as early cancer recurrence. PAI-1 statistically correlated with genes typically induced by YAP, such as connective tissue growth factor (CTGF) and cysteine rich angiogenic inducer 61 (CYR61) or YAP-dependent gene signatures (CIN4/25). In vitro, YAP inhibition diminished the expression and secretion of PAI-1 in murine and human liver cancer cell lines. PAI-1 affected the expression of genes involved in cellular senescence and oncogene-induced senescence was confirmed in YAPS127A transgenic mice. Silencing of TEAD4 as well as treatment with the YAP/TEAD interfering substance Verteporfin reduced PAI-1 expression. ChIP analyses confirmed the binding of YAP and TEAD4 to the gene promoter of PAI-1 (SERPINE1). CONCLUSIONS: These results demonstrate that the oncogene YAP changes the secretome response of hepatocytes and hepatocyte-derived tumor cells. In this context, the secreted protein PAI-1 is transcriptionally regulated by YAP in hepatocarcinogenesis. Perturbation of these YAP-dependent communication hubs including PAI-1 may represent a promising pharmacological approach in tumors with YAP overexpression. Video abstract.

YAP Orchestrates Heterotypic Endothelial Cell Communication via HGF/c-MET Signaling in Liver Tumorigenesis.

The oncogene yes-associated protein (YAP) controls liver tumor initiation and progression via cell extrinsic functions by creating a tumor-supporting environment in conjunction with cell autonomous mechanisms. However, how YAP controls organization of the microenvironment and in particular the vascular niche, which contributes to liver disease and hepatocarcinogenesis, is poorly understood. To investigate heterotypic cell communication, we dissected murine and human liver endothelial cell (EC) populations into liver sinusoidal endothelial cells (LSEC) and continuous endothelial cells (CEC) through histomorphological and molecular characterization. In YAPS127A-induced tumorigenesis, a gradual replacement of LSECs by CECs was associated with dynamic changes in the expression of genes involved in paracrine communication. The formation of new communication hubs connecting CECs and LSECs included the hepatocyte growth factor (Hgf)/c-Met signaling pathway. In hepatocytes and tumor cells, YAP/TEA domain transcription factor 4 (TEAD4)-dependent transcriptional induction of osteopontin (Opn) stimulated c-Met expression in EC with CEC phenotype, which sensitized these cells to the promigratory effects of LSEC-derived Hgf. In human hepatocellular carcinoma, the presence of a migration-associated tip-cell signature correlated with poor clinical outcome and the loss of LSEC marker gene expression. The occurrence of c-MET-expressing CECs in human liver cancer samples was confirmed at the single-cell level. In summary, YAP-dependent changes of the liver vascular niche comprise the formation of heterologous communication hubs in which tumor cell-derived factors modify the cross-talk between LSECs and CECs via the HGF/c-MET axis. SIGNIFICANCE: YAP-dependent changes of the liver vascular niche comprise the formation of heterologous communication hubs in which tumor cell-derived factors modify the cross-talk between EC subpopulations. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/24/5502/F1.large.jpg.

YAP-dependent induction of UHMK1 supports nuclear enrichment of the oncogene MYBL2 and proliferation in liver cancer cells.

The oncogene yes-associated protein (YAP) is a key modifier of liver homeostasis and regulates mitosis in hepatocytes as well as in malignantly transformed cells. However, the question of how YAP supports cell proliferation in hepatocellular carcinoma (HCC) is not well understood. Here we identified U2AF momology motif kinase 1 (UHMK1) as a direct transcriptional target of YAP and the transcription factor forkhead box M1 (FOXM1), which supports HCC cell proliferation but not migration. Indeed, UHMK1 stimulates the expression of genes that are specific for cell cycle regulation and which are known downstream effectors of YAP. By using BioID labeling and mass spectrometry, the dimerization partner, RB-like, E2F and multi-vulval class B (DREAM) complex constituent MYB proto-oncogene like 2 (MYBL2, B-MYB) was identified as a direct UHMK1 interaction partner. Like YAP, UHMK1 stimulates nuclear enrichment of MYBL2, which is associated HCC cell proliferation and the expression of the cell cycle regulators CCNB1, CCNB2, KIF20A, and MAD2L1. The association between YAP, UHMK1, MYBL2, and proliferation was confirmed in YAPS127A-transgenic mice and human HCC tissues. In summary, we provide a model by which YAP supports cell proliferation through the induction of important cell cycle regulators in a UHMK1- and MYBL2-dependent manner.

Three-dimensional reconstruction of prostate cancer architecture with serial immunohistochemical sections: hallmarks of tumour growth, tumour compartmentalisation, and implications for grading and heterogeneity.

AIMS: Conventional morphology of prostate cancer considers only the two-dimensional (2D) architecture of the tumour. Our aim was to examine the feasibility of three-dimensional (3D) reconstruction of tumour morphology based on multiple consecutive histological sections and to decipher relevant features of prostate cancer architecture. METHODS AND RESULTS: Seventy-five consecutive histological sections (5 µm) of a typical prostate adenocarcinoma (Gleason score of 3 + 4 = 7) were immunostained (pan-cytokeratin) and scanned for further 3D reconstructions with fiji/imagej software. The main findings related to the prostate cancer architecture in this case were: (i) continuity of all glands, with the tumour being an integrated system, even in Gleason pattern 4 with poorly formed glands-no short-range migration of cells by Gleason pattern 4 (poorly formed glands); (ii) no repeated interconnections between the glands, with a tumour building a tree-like branched structure with very 'plastic' branches (maximal depth of investigation 375 µm); (iii) very stark compartmentalisation of the tumour related to extensive branching, the coexistence of independent terminal units of such branches in one 2D slice explaining intratumoral heterogeneity; (iv) evidence of a craniocaudal growth direction in interglandular regions of the prostate and for a lateromedial growth direction in subcapsular posterolateral regions; and (v) a 3D architecture-based description of Gleason pattern 4 with poorly formed glands, and its continuum with Gleason pattern 3. CONCLUSIONS: Consecutive histological sections provide high-quality material for 3D reconstructions of the tumour architecture, with excellent resolution. The reconstruction of multiple regions in this typical case of a Gleason score 3 + 4 = 7 tumour provides insights into relevant aspects of tumour growth, the continuity of Gleason patterns 3 and 4, and tumour heterogeneity.

Cytoplasmic localization of the cell polarity factor scribble supports liver tumor formation and tumor cell invasiveness.

The loss of epithelial cell polarity plays an important role in the development and progression of liver cancer. However, the specific molecular mechanisms supporting tumor initiation and progression are poorly understood. In this study, transcriptome data and immunofluorescence stains of tissue samples derived from hepatocellular carcinoma (HCC) patients revealed that overexpression associated with cytoplasmic localization of the basolateral cell polarity complex protein scribble (Scrib) correlated with poor prognosis of HCC patients. In comparison with HCC cells stably expressing wild-type Scrib (ScribWT ), mutated Scrib with enforced cytoplasmic enrichment (ScribP305L ) induced AKT signaling through the destabilization of phosphatase and tensin homolog (PTEN) and PH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1). Cytoplasmic ScribP305L stimulated a gene signature and a phenotype characteristic for epithelial to mesenchymal transition (EMT) and HCC cell invasiveness. ScribP305L -dependent invasion was mediated by the activator protein 1 (AP-1) constituents ATF2 and JunB through induction of paracrine-acting secreted protein acidic and cysteine-rich (SPARC). Coexpression of ScribP305L and the oncogene c-MYC through hydrodynamic gene delivery in mouse livers promoted tumor formation and increased abundance of pAKT, pATF2, and SPARC in comparison with controls. Finally, cytoplasmic Scrib localization correlated with AKT and ATF2 phosphorylation in human HCC tissues, and the ScribP305L -dependent gene signature was enriched in cancer patients with poor prognosis. CONCLUSION: Perturbation of hepatocellular polarity due to overexpression and cytoplasmic enrichment of Scrib supports tumor initiation and HCC cell dissemination through specific molecular mechanisms. Biomarker signatures identified in this study can be used for the identification of HCC patients with higher risk for the development of metastasis. (Hepatology 2018;67:1842-1856).

Induction of Chromosome Instability by Activation of Yes-Associated Protein and Forkhead Box M1 in Liver Cancer.

BACKGROUND & AIMS: Many different types of cancer cells have chromosome instability. The hippo pathway leads to phosphorylation of the transcriptional activator yes-associated protein 1 (YAP1, YAP), which regulates proliferation and has been associated with the development of liver cancer. We investigated the effects of hippo signaling via YAP on chromosome stability and hepatocarcinogenesis in humans and mice. METHODS: We analyzed transcriptome data from 242 patients with hepatocellular carcinoma (HCC) to search for gene signatures associated with chromosomal instability (CIN); we investigated associations with overall survival time and cancer recurrence using Kaplan-Meier curves. We analyzed changes in expression of these signature genes, at mRNA and protein levels, after small interfering RNA-mediated silencing of YAP in Sk-Hep1, SNU182, HepG2, or pancreatic cancer cells, as well as incubation with thiostrepton (an inhibitor of forkhead box M1 [FOXM1]) or verteporfin (inhibitor of the interaction between YAP and TEA domain transcription factor 4 [TEAD4]). We performed co-immunoprecipitation and chromatin immunoprecipitation experiments. We collected liver tissues from mice that express a constitutively active form of YAP (YAPS127A) and analyzed gene expression signatures and histomorphologic parameters associated with chromosomal instability. Mice were given injections of thiostrepton and livers were collected and analyzed by immunoblotting, immunohistochemistry, histology, and real-time polymerase chain reaction. We performed immunohistochemical analyses on tissue microarrays of 105 HCCs and 7 nontumor liver tissues. RESULTS: Gene expression patterns associated with chromosome instability, called CIN25 and CIN70, were detected in HCCs from patients with shorter survival time or early cancer recurrence. TEAD4 and YAP were required for CIN25 and CIN70 signature expression via induction and binding of FOXM1. Disrupting the interaction between YAP and TEAD4 with verteporfin, or inhibiting FOXM1 with thiostrepton, reduced the chromosome instability gene expression patterns. Hyperplastic livers and tumors from YAPS127A mice had increased CIN25 and CIN70 gene expression patterns, aneuploidy, and defects in mitosis. Injection of YAPS127A mice with thiostrepton reduced liver overgrowth and signs of chromosomal instability. In human HCC tissues, high levels of nuclear YAP correlated with increased chromosome instability gene expression patterns and aneuploidy. CONCLUSIONS: By analyzing cell lines, genetically modified mice, and HCC tissues, we found that YAP cooperates with FOXM1 to contribute to chromosome instability. Agents that disrupt this pathway might be developed as treatments for liver cancer. Transcriptome data are available in the Gene Expression Omnibus public database (accession numbers: GSE32597 and GSE73396).

Impact of wall shear stress and ligand avidity on binding of anti-CD146-coated nanoparticles to murine tumor endothelium under flow.

The endothelial phenotype of tumor blood vessels differs from the liver and forms an important base for endothelium-specific targeting by antibody-coated nanoparticles. Although differences of shear stress and ligand avidity can modulate the nanoparticle binding to endothelium, these mechanisms are still poorly studied. This study analyzed the binding of antibody-coated nanoparticles to tumor and liver endothelium under controlled flow conditions and verified this binding in tumor models in vivo. Binding of anti-CD146-coated nanoparticles, but not of antibody was significantly reduced under increased wall shear stress and the degree of nanoparticle binding correlated with the avidity of the coating. The intravascular wall shear stress favors nanoparticle binding at the site of higher avidity of endothelial epitope which additionally promotes the selectivity to tumor endothelium. After intravenous application in vivo, pegylated self-coated nanoparticles showed specific binding to tumor endothelium, whereas the nanoparticle binding to the liver endothelium was very low. This study provides a rationale that selective binding of mAb-coated nanoparticles to tumor endothelium is achieved by two factors: higher expression of endothelial epitope and higher nanoparticle shearing from liver endothelium. The combination of endothelial marker targeting and the use of shear stress-controlled nanoparticle capture can be used for selective intratumoral drug delivery.

Selective targeting of liver cancer with the endothelial marker CD146.

Hepatocellular carcinomas are well-vascularized tumors; the endothelial cells in these tumors have a specific phenotype. Our aim was to develop a new approach for tumor-specific drug delivery with monoclonal antibody targeting of endothelial ligands. CD146, a molecule expressed on the endothelial surface of hepatocellular carcinoma, was identified as a promising candidate for targeting. In the present study, endothelial cells immediately captured circulating anti-CD146 (ME-9F1) antibody, while antibody binding in tumors was significantly higher than in hepatic endothelium. Macroscopically, after intravenous injection, there were no differences in the mean accumulation of anti-CD146 antibody in tumor compared to liver tissue , due to a compensating higher blood vessel density in the liver tissue. Additional blockade of nontumoral epitopes and intra-arterial administration, improved selective antibody capture in the tumor microvasculature and largely prevented antibody distribution in the lung and liver. The potential practical use of this approach was demonstrated by imaging of radionuclide-labeled ME-9F1 antibody, which showed excellent tumor-selective uptake. Our results provide a promising principle for the use of endothelial markers for intratumoral drug delivery. Tumor endothelium-based access might offer new opportunities for the imaging and therapy of hepatocellular carcinoma and other liver malignancies.